Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of the first image in a sequence for a display screen or portion thereof with transitional graphical user interface showing our new design;

FIG. 2 is the second image thereof;

FIG. 3 is the third image thereof;

FIG. 4 is a front perspective view of the first image of FIG. 1 ;

FIG. 5 is a front perspective view of the second image of FIG. 2 ;

FIG. 6 is a front perspective view of the third image of FIG. 3 ;

FIG. 7 is a right side view of the first image of FIG. 1 ;

FIG. 8 is a right side view of the second image of FIG. 2 ; and,

FIG. 9 is a right side view of the third image of FIG. 3 .

The outermost broken lines in the drawings showing an electronic device illustrate environmental subject matter that forms no part of the claimed design. The broken line rounded rectangle within the outermost broken lines in the drawings illustrates a display screen or portion thereof that forms no part of the claimed design. The remaining broken lines in the drawings illustrate portions of the graphical user interface that form no part of the claimed design.

The appearance of the transitional image sequentially transitions between the images shown in FIGS. 1-3, 4-6, and 7-9 , respectively. The process or period in which one image transitions to another image forms no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with transitional graphical user interface, as shown and described. 